1. Technical Field
The present invention relates to an ink composition for ink jet recording.
2. Related Art
In the related art, an ink jet recording method for recording an image or text by fine ink droplets discharged from nozzles of a head for ink jet recording is known. As the ink composition used in such an ink jet recording method, an ink composition containing a coloring material (pigment, dye, or the like), a surfactant, water, an organic solvent, or the like is widely used.
Since the surfactant among components included in the ink composition for ink jet recording increases permeability and wetting and spreading properties of the ink composition with respect to a recording medium, the surfactant can improve an image quality of a recorded image. Among such surfactants, an acetylene glycol-based surfactant (for example, acetylene glycol and acetylene glycol derivatives) is attracting attention due to the fact that this surfactant is excellent in a function of improving the permeability and the wetting and spreading properties of the ink composition with respect to a recording medium and has an excellent defoaming property.
For example, JP-A-2013-18951 discloses an ink composition for ink jet recording which contains an acetylene glycol-based surfactant. JP-A-2013-18951 discloses an ink composition containing two kinds of ethylene oxide adduct of acetylene glycol having a specific structure and a HLB value, from the fact that an effect preventing reduction of a dot diameter is excellent while good discharging property is maintained.
In a case of recording an image on a recording medium (for example, plain paper of which a main component is cellulose) having favorable absorbability for ink (water) using the ink composition described in JP-A-2013-18951, the ink is likely to penetrate into the recording medium, and thus, an image with favorable image quality in which aggregation of ink droplets or color irregularity of an image is suppressed and favorable fixability tends to be obtained.
However, even in a case of recording an image on recycled paper among plain papers which have favorable absorbability of ink, aggregation of ink droplets or color irregularity of an image occurs on the recording medium, and due to this, the image quality deteriorates. Hydrophobic components such as inorganic compounds including calcium carbonate and kaolin, stearic acid, and resin in addition to cellulose are largely included in the recycled paper, and thus, a hydrophilic region and a hydrophobic region are mixed on the paper surface. For this reason, a problem in which penetration speed of an ink is different depending on the position to which ink droplets are adhered occurs, and deterioration of image quality such as aggregation or color irregularity occurs in some cases.
In addition, in a case of recording an image on a recording medium (for example, enamel paper such as art paper or coated paper) having low absorbability of ink (water) using the ink composition described in JP-A-2013-18951, the ink composition is less likely to penetrate into the recording medium, or less likely to wet and spread on the recording medium, and thus, due to occurrence of aggregation of ink droplets on the recording medium, color irregularity of the image, bleeding of the image (bleed) or the like, image quality deteriorates or fixability of an image deteriorates.
In this manner, it is difficult to record an image with favorable image quality and fixability on various types of recording medium having different absorbability of ink using the ink composition having one composition.
Furthermore, the ink composition of JP-A-2013-18951 has low permeability with respect to a recording medium having low absorbability of ink and does not exhibit sufficient penetration speed with respect to a recording medium having favorable absorbability of ink, and thus, time is required for promoting wetting and spreading or penetration of ink, and a recording speed of an image tends to decrease.